More than 15 million people in the U.S. have symptoms of a skin disorder, for example dermatitis. Dermatitis is a term literally meaning “inflammation of the skin”. It is usually used to refer to eczema, and several different forms are recognized including cercarial dermatitis, dermatitis herpetiformis, atopic dermatitis, seborrhoeic dermatitis, and contact dermatitis.
Cercarial dermatitis is a short-term, immune reaction occurring in the skin of humans that have been infected by water-borne trematode parasites. Symptoms, which include itchy, raised papules, commonly occur within hours of infection and do not generally last more than a week.
Dermatitis herpetiformis (DH) or Duhring's Disease, is a skin disorder often associated with celiac disease. It is a chronic, extremely itchy rash consisting of papules and vesicles. Dermatitis herpetiformis is associated with sensitivity of the intestine to gluten in the diet.
Atopic dermatitis, sometimes called eczema, is a kind of dermatitis, an atopic skin disease. Skin of an affected person reacts to irritants, food and air allergens and becomes red, flaky and very itchy. It also becomes vulnerable to inflammations caused by bacteria. Atopic dermatitis very often occurs together with other atopic diseases like hay fever, asthma and conjunctivitis.
Seborrheic dermatitis is a disease that causes flaking of the skin. It particularly affects the sebum-gland rich areas of skin. It can also affect the face and chest, and the creases of the arms, legs and groin. Seborrheic dermatitis usually causes the skin to look a little greasy and scaly or flaky. It is thought to be caused by a fungal infection caused by the yeast Malassezia furfur in individuals with decreased immunity and increased sebum production.
Domestic pets and animals also suffer from skin disorders including atopic dermatitis. Atopic dermatitis is one of the most common skin diseases of dogs. As with humans, the principal causes of atopic dermatitis are external allergens, e.g., house dust mites, pollens, molds, etc. Treatments include allergen avoidance and prevention of allergen contact, symptomatic anti-inflammatory pharmacotherapy, allergen-specific immunotherapy, and antimicrobial therapy.
Topical treatments for seborrheic dermatitis include shampoos containing coal tar, zinc pyrithione, salicylic acid or ketoconazole as active ingredients. Salicylic acid helps dissolve skin flakes. Pyrithione helps to kill fungus. Coal tar is believed to help reduce inflammation and sebum and to prevent the reoccurrence of flakes and scalp build-up. Coal tar is a combination of compounds produced from by-products of coal distillation, and a number of studies report that coal tar is toxic or carcinogenic. For example, coal tar contains benzo[a]pyrene, a highly potent carcinogen.
Studies have shown that topical application of compositions containing coal tar are toxic and may cause DNA damage (Thein, N. et al. (2000) Muta Res 468(2):117-24; Rojas, M. et al. (2001) Carcinogenesis 22(7):1015-8; Vogel, U. et al. (2001) Pharmacol Toxicol. 89(1):30-4).
Green tea polyphenols are known phytochemicals that have antioxidant, anti-microbial, anticancer, and anti-inflammation properties, and were recently found to promote skin homeostasis and protect against autoimmune diseases. Extracts of green tea have been used for medicinal purposes for generations in China. Green tea polyphenols in extracts are mostly water-soluble, and can be easily oxidized if they are mixed in emulsions containing water, such as detergents and cosmetics. Additionally, conventional green tea polyphenols are not permeable to the skin, and therefore their activity is significantly reduced.
Thus, there is a need for additional green tea polyphenol compositions and methods for preventing and treating skin disorders or symptoms thereof.